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<FONT color="green">001</FONT>    <a name="line.1"></a>
<FONT color="green">002</FONT>    /*<a name="line.2"></a>
<FONT color="green">003</FONT>     * Copyright (C) 2011 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<FONT color="green">004</FONT>     *<a name="line.4"></a>
<FONT color="green">005</FONT>     * $Id: NullModemOutputStream.html 89 2011-04-25 18:41:56Z archie.cobbs $<a name="line.5"></a>
<FONT color="green">006</FONT>     */<a name="line.6"></a>
<FONT color="green">007</FONT>    <a name="line.7"></a>
<FONT color="green">008</FONT>    package org.dellroad.stuff.io;<a name="line.8"></a>
<FONT color="green">009</FONT>    <a name="line.9"></a>
<FONT color="green">010</FONT>    import java.io.FilterOutputStream;<a name="line.10"></a>
<FONT color="green">011</FONT>    import java.io.IOException;<a name="line.11"></a>
<FONT color="green">012</FONT>    import java.io.InputStream;<a name="line.12"></a>
<FONT color="green">013</FONT>    import java.io.PipedInputStream;<a name="line.13"></a>
<FONT color="green">014</FONT>    import java.io.PipedOutputStream;<a name="line.14"></a>
<FONT color="green">015</FONT>    <a name="line.15"></a>
<FONT color="green">016</FONT>    /**<a name="line.16"></a>
<FONT color="green">017</FONT>     * Presents an {@link java.io.OutputStream OutputStream} interface given a {@link ReadCallback} that can read from an<a name="line.17"></a>
<FONT color="green">018</FONT>     * {@link InputStream}. A separate thread is created to perform the actual reading.<a name="line.18"></a>
<FONT color="green">019</FONT>     *<a name="line.19"></a>
<FONT color="green">020</FONT>     * &lt;p&gt;<a name="line.20"></a>
<FONT color="green">021</FONT>     * If data is written beyond what the reader is willing to consume, an {@link IOException} is thrown.<a name="line.21"></a>
<FONT color="green">022</FONT>     *<a name="line.22"></a>
<FONT color="green">023</FONT>     * @since 1.0.82<a name="line.23"></a>
<FONT color="green">024</FONT>     */<a name="line.24"></a>
<FONT color="green">025</FONT>    public class NullModemOutputStream extends FilterOutputStream {<a name="line.25"></a>
<FONT color="green">026</FONT>    <a name="line.26"></a>
<FONT color="green">027</FONT>        private final PipedInputStream input;<a name="line.27"></a>
<FONT color="green">028</FONT>    <a name="line.28"></a>
<FONT color="green">029</FONT>        /**<a name="line.29"></a>
<FONT color="green">030</FONT>         * Constructor.<a name="line.30"></a>
<FONT color="green">031</FONT>         *<a name="line.31"></a>
<FONT color="green">032</FONT>         * @param reader    {@link InputStream} reader callback<a name="line.32"></a>
<FONT color="green">033</FONT>         * @param name      name for this instance; used to create the name of the background thread<a name="line.33"></a>
<FONT color="green">034</FONT>         */<a name="line.34"></a>
<FONT color="green">035</FONT>        public NullModemOutputStream(final ReadCallback reader, String name) {<a name="line.35"></a>
<FONT color="green">036</FONT>            super(new PipedOutputStream());<a name="line.36"></a>
<FONT color="green">037</FONT>    <a name="line.37"></a>
<FONT color="green">038</FONT>            // Sanity check<a name="line.38"></a>
<FONT color="green">039</FONT>            if (reader == null)<a name="line.39"></a>
<FONT color="green">040</FONT>                throw new IllegalArgumentException("null reader");<a name="line.40"></a>
<FONT color="green">041</FONT>    <a name="line.41"></a>
<FONT color="green">042</FONT>            // Create other end of pipe<a name="line.42"></a>
<FONT color="green">043</FONT>            try {<a name="line.43"></a>
<FONT color="green">044</FONT>                this.input = new PipedInputStream(this.getPipedOutputStream());<a name="line.44"></a>
<FONT color="green">045</FONT>            } catch (IOException e) {<a name="line.45"></a>
<FONT color="green">046</FONT>                throw new RuntimeException("unexpected exception", e);<a name="line.46"></a>
<FONT color="green">047</FONT>            }<a name="line.47"></a>
<FONT color="green">048</FONT>    <a name="line.48"></a>
<FONT color="green">049</FONT>            // Launch reader thread<a name="line.49"></a>
<FONT color="green">050</FONT>            Thread thread = new ReaderThread(reader, input, name);<a name="line.50"></a>
<FONT color="green">051</FONT>            thread.setDaemon(true);<a name="line.51"></a>
<FONT color="green">052</FONT>            thread.start();<a name="line.52"></a>
<FONT color="green">053</FONT>        }<a name="line.53"></a>
<FONT color="green">054</FONT>    <a name="line.54"></a>
<FONT color="green">055</FONT>        /**<a name="line.55"></a>
<FONT color="green">056</FONT>         * Get the wrapped stream cast as a {@link PipedOutputStream}.<a name="line.56"></a>
<FONT color="green">057</FONT>         */<a name="line.57"></a>
<FONT color="green">058</FONT>        protected PipedOutputStream getPipedOutputStream() {<a name="line.58"></a>
<FONT color="green">059</FONT>            return (PipedOutputStream)this.out;<a name="line.59"></a>
<FONT color="green">060</FONT>        }<a name="line.60"></a>
<FONT color="green">061</FONT>    <a name="line.61"></a>
<FONT color="green">062</FONT>        /**<a name="line.62"></a>
<FONT color="green">063</FONT>         * Ensure output stream is closed when this instance is no longer referenced.<a name="line.63"></a>
<FONT color="green">064</FONT>         *<a name="line.64"></a>
<FONT color="green">065</FONT>         * &lt;p&gt;<a name="line.65"></a>
<FONT color="green">066</FONT>         * This ensures the reader thread wakes up (and exits, avoiding a memory leak) when an instance of this class<a name="line.66"></a>
<FONT color="green">067</FONT>         * is created but never read from.<a name="line.67"></a>
<FONT color="green">068</FONT>         */<a name="line.68"></a>
<FONT color="green">069</FONT>        @Override<a name="line.69"></a>
<FONT color="green">070</FONT>        protected void finalize() throws Throwable {<a name="line.70"></a>
<FONT color="green">071</FONT>            try {<a name="line.71"></a>
<FONT color="green">072</FONT>                try {<a name="line.72"></a>
<FONT color="green">073</FONT>                    this.getPipedOutputStream().close();<a name="line.73"></a>
<FONT color="green">074</FONT>                } catch (IOException e) {<a name="line.74"></a>
<FONT color="green">075</FONT>                    // ignore<a name="line.75"></a>
<FONT color="green">076</FONT>                }<a name="line.76"></a>
<FONT color="green">077</FONT>            } finally {<a name="line.77"></a>
<FONT color="green">078</FONT>                super.finalize();<a name="line.78"></a>
<FONT color="green">079</FONT>            }<a name="line.79"></a>
<FONT color="green">080</FONT>        }<a name="line.80"></a>
<FONT color="green">081</FONT>    <a name="line.81"></a>
<FONT color="green">082</FONT>        /**<a name="line.82"></a>
<FONT color="green">083</FONT>         * Callback interface used by {@link NullModemOutputStream}.<a name="line.83"></a>
<FONT color="green">084</FONT>         */<a name="line.84"></a>
<FONT color="green">085</FONT>        public interface ReadCallback {<a name="line.85"></a>
<FONT color="green">086</FONT>    <a name="line.86"></a>
<FONT color="green">087</FONT>            /**<a name="line.87"></a>
<FONT color="green">088</FONT>             * Read from the given input stream.<a name="line.88"></a>
<FONT color="green">089</FONT>             *<a name="line.89"></a>
<FONT color="green">090</FONT>             * &lt;p&gt;<a name="line.90"></a>
<FONT color="green">091</FONT>             * This method will be invoked (once) asynchronously in a dedicated reader thread.<a name="line.91"></a>
<FONT color="green">092</FONT>             * &lt;/p&gt;<a name="line.92"></a>
<FONT color="green">093</FONT>             *<a name="line.93"></a>
<FONT color="green">094</FONT>             * @throws IOException if an I/O error occurs<a name="line.94"></a>
<FONT color="green">095</FONT>             */<a name="line.95"></a>
<FONT color="green">096</FONT>            void readFrom(InputStream output) throws IOException;<a name="line.96"></a>
<FONT color="green">097</FONT>        }<a name="line.97"></a>
<FONT color="green">098</FONT>    <a name="line.98"></a>
<FONT color="green">099</FONT>        /**<a name="line.99"></a>
<FONT color="green">100</FONT>         * Reader thread. This is designed to not hold a reference to the {@link NullModemOutputStream}.<a name="line.100"></a>
<FONT color="green">101</FONT>         */<a name="line.101"></a>
<FONT color="green">102</FONT>        private static class ReaderThread extends Thread {<a name="line.102"></a>
<FONT color="green">103</FONT>    <a name="line.103"></a>
<FONT color="green">104</FONT>            private final ReadCallback reader;<a name="line.104"></a>
<FONT color="green">105</FONT>            private final PipedInputStream input;<a name="line.105"></a>
<FONT color="green">106</FONT>    <a name="line.106"></a>
<FONT color="green">107</FONT>            ReaderThread(ReadCallback reader, PipedInputStream input, String name) {<a name="line.107"></a>
<FONT color="green">108</FONT>                super(name);<a name="line.108"></a>
<FONT color="green">109</FONT>                this.reader = reader;<a name="line.109"></a>
<FONT color="green">110</FONT>                this.input = input;<a name="line.110"></a>
<FONT color="green">111</FONT>            }<a name="line.111"></a>
<FONT color="green">112</FONT>    <a name="line.112"></a>
<FONT color="green">113</FONT>            @Override<a name="line.113"></a>
<FONT color="green">114</FONT>            public void run() {<a name="line.114"></a>
<FONT color="green">115</FONT>                try {<a name="line.115"></a>
<FONT color="green">116</FONT>                    this.reader.readFrom(this.input);<a name="line.116"></a>
<FONT color="green">117</FONT>                } catch (IOException e) {<a name="line.117"></a>
<FONT color="green">118</FONT>                    // ignore - writer will get another IOException because pipe is about to be broken<a name="line.118"></a>
<FONT color="green">119</FONT>                } finally {<a name="line.119"></a>
<FONT color="green">120</FONT>                    try {<a name="line.120"></a>
<FONT color="green">121</FONT>                        this.input.close();<a name="line.121"></a>
<FONT color="green">122</FONT>                    } catch (IOException e) {<a name="line.122"></a>
<FONT color="green">123</FONT>                        // ignore<a name="line.123"></a>
<FONT color="green">124</FONT>                    }<a name="line.124"></a>
<FONT color="green">125</FONT>                }<a name="line.125"></a>
<FONT color="green">126</FONT>            }<a name="line.126"></a>
<FONT color="green">127</FONT>        }<a name="line.127"></a>
<FONT color="green">128</FONT>    }<a name="line.128"></a>
<FONT color="green">129</FONT>    <a name="line.129"></a>




























































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